My Java application needs this library libswt-webkit-gtk-3-jni to run successfully. So if the user doesn't have this library installed, I want Ubuntu Software Center to be launched and tell the user "you should have this library".

I think (without knowing Java!) that it would be Process process = new ProcessBuilder("/usr/bin/software-center", "libswt-webkit-gtk-3-jni").start();. No need to start an xterm, when you can start the software center directly. Can you try it for me?
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JanuaryOct 8 '12 at 10:49